Data needs in studies on equity in health and access to care--ethical considerations

In order to study equity in health and access to care in an appropriate way, data are needed on an individual level and must include information about health, mortality, morbidity, utilization of care, age, sex, residential area, family situation and the social and economic circumstances of each individual. These data must be collected at several points of time during a life cycle. This is a demanding task requiring many resources and methodological and ethical considerations. The ethical and political trade-off is between our demand for knowledge and a fair distribution of resources in order to achieve equity in health and access to care and the need to administrate sensitive data without threatening personal integrity. In presenting results from Swedish studies, it is argued that the benefits of using registers for this kind of epidemiological research by far outweigh the risk of using registers.